The present invention relates generally to electrical power storage systems, and more particularly, to methods and systems for making lithium-ion batteries.
Traditional lithium ion batteries lack sufficient energy density (Watt-hours/kilogram) for many electrical systems. By way of example, the insufficient energy density of traditional lithium-ion batteries limits the electric vehicle driving range between recharges. Electric vehicles are a major step in moving transportation systems of a modem, energy based economy away from greenhouse gas emitting fossil fuel engines.
In view of the foregoing, there is a need for an electrical energy storage solution with a greater energy density than traditional lithium-ion batteries.
Broadly speaking, the present invention fills these needs by providing a lithium-ion battery using microparticles as an electrical energy storage solution electrical power storage system. It should be appreciated that the present invention can be implemented in numerous ways, including as a process, an apparatus, a system, computer readable media, or a device. Several inventive embodiments of the present invention are described below.
One embodiment provides a system and method of forming a silicon-hybrid anode material. The silicon-hybrid anode material including a microparticle mixture of a quantity of silicon microparticles and a quantity of metal microparticles intermixed with the quantity of silicon microparticles in a selected ratio. The microparticle mixture is formed in a silicon-hybrid anode material layer having a thickness of between about 2 and about 15 μm.
The microparticle mixture can include a quantity of at least one binder material. The microparticle mixture can be heated and the quantity of at least one binder material is substantially evaporated away. The microparticle mixture can be annealed.
The quantity of silicon microparticles can have a size range of between about 1 micrometer and about 20 micrometers. The quantity of metal microparticles has a size range of between about 1 micrometer and about 30 micrometers. The size of the silicon microparticles can be substantially equal to the size of the metal microparticles.
The selected ratio of the microparticle mixture includes between about 10 percent and about 40 percent, by weight, of silicon microparticles and between about 90 percent and about 60 percent, by weight, of metal microparticles. The binder is between about 5 percent and about 10 percent by weight of the microparticle mixture.
At least one silicon-hybrid anode material layer can be included in a battery. The battery can be a lithium-ion battery. The lithium-ion battery can also include a lithium containing electrolyte, a quantity of separator material is included within the lithium containing electrolyte and a cathode disposed on a side of the electrolyte opposite from the at least one silicon-hybrid anode material layer.
Another embodiment provides a method of forming a silicon-hybrid anode material. The method includes forming a quantity of silicon microparticles, forming a quantity of metal microparticles, mixing the quantity of silicon microparticles and the quantity of metal microparticles in a selected ratio to form a microparticle mixture and forming the microparticle mixture into a silicon-hybrid anode material layer having a thickness of between about 2 and about 15 μm.
Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.